Precious Metal Recovery & Extraction System

— Turnkey Precious Metal Recovery And Extraction System

A YuSai precious metal recovery and extraction system is one engineered flowsheet — not a single machine — that takes precious-metal-bearing solids, process solutions and dilute rinse water from the same plant and turns them into assayed, saleable metal. It reaches 95% or higher comprehensive recovery on qualified multi-metal feed, and the electrolytic route recovers more than 99% of the metal dissolved in high-concentration streams while taking the working solution down to parts-per-million residual levels. Gold and silver are refined to 99.99% (4N) as standard with 99.999% (5N) achievable on a second pass; platinum and palladium are delivered at 99.95% or above and rhodium at 99.90%. The system treats all three recovery points of a production line in one scope — the process tank, the recovery tank behind it and the rinse water downstream — instead of harvesting only the easy metal.

Product Overview

A precious metal recovery and extraction system is an integrated process plant that recovers gold, silver, platinum, palladium and rhodium from solid waste, concentrated process solutions and dilute effluent, then refines those metals into assayed product that can be sold, returned to production or submitted for custody transfer. It combines mechanical pre-treatment, thermal enrichment, chemical dissolution, selective separation and electrolytic refining in one engineered circuit, with the off-gas and wastewater treatment that make the circuit licensable.

Most recovery projects do not fail because a technology is missing. They fail because one of three streams is left untreated. The first is the process tank itself: spent plating baths, stripping solutions and etching solutions that still hold metal at high concentration. The second is the recovery tank behind it: drag-out and collected process solution that carries metal out of the tank with every rack. The third is the rinse water: dilute, but continuous, and the usual reason a plant still reports metal in its final effluent. A YuSai system is designed around all three points as one flowsheet, which is why a single project can combine an electrolytic recovery cell running on a high-concentration bath with ion exchange and activated carbon columns polishing a stream that measures parts per million.

Solid feedstock — printed circuit boards, anode slime, spent catalysts, jewellery sweeps, plating sludge — follows a three-stage sequence inside the same system. Stage one, mechanical pre-treatment: material is dismantled, crushed and separated by magnetic, eddy-current, electrostatic and gravity methods, so metals are liberated from plastics, glass fibre and other non-metallics. Stage two, thermal and chemical extraction: organic content is destroyed and values are concentrated either pyrometallurgically in a rotary or TBRC-type furnace, or hydrometallurgically through acid, chloride or alkaline leaching, after which the metal ions are captured from solution by activated carbon adsorption, ion exchange resin, solvent extraction or selective precipitation. Stage three, electrolytic refining: dissolved or captured metals are deposited onto the cathode of an electrolytic cell, then melted, cast and assayed.

The electrolytic stage is where the design earns its recovery rate. YuSai cells use a rotating cathode together with high-frequency pulse intelligent electrolysis, which keeps the boundary layer at the cathode in motion, allows deposition to continue as the concentration falls, and produces a deposit that strips off cleanly as plate, crystal or powder rather than as loose sludge. On the concentrated route this means no reagents and no electrolytic accelerators are consumed beyond electricity: the recovery step is a clean electrochemical reduction. On the dilute route, ion exchange resin and activated carbon are selected against the specific metal and solution chemistry, with simplified column replacement so that maintenance does not interrupt production.

Every project starts in the laboratory. We assay the customer’s own sample by fire assay, XRF and wet chemical analysis, then run bench-scale leaching, adsorption and deposition tests to confirm the recoverable content and the separation sequence before any equipment is sized. Equipment is configured against that test result rather than against a fixed catalogue model, and the system is handed over only after it produces metal at the agreed specification.

Application Scenarios

A recovery and extraction system is installed wherever metal-bearing material costs more to lose than it does to process:

Electroplating and surface finishing plants — recovery from gold, silver, palladium and rhodium plating baths, drag-out tanks, rinse water and spent electrolytes, with tank-side cells for concentrated baths and resin or carbon columns for dilute rinses.
Semiconductor and electronics manufacturing — recovery from waste plating solutions, process effluent and rinsing solutions generated in semiconductor, connector, lead-frame and electronic component production.
>PCB and circuit board production — recovery of gold and silver from gold etching solutions, stripping and deplating solutions, iodine and iodide etching solutions, and spent plating waste solution.
E-waste and WEEE recycling plants — recovery of gold, silver and palladium from printed circuit boards, CPUs, RAM modules and connectors after mechanical dismantling, including desoldering and component removal.
Precious metal refineries and mints — refining of doré, scrap, sweeps and recycled feedstock into certified gold and silver bullion.
Copper, lead and zinc smelters — treatment of anode slime from the tank house as a payable precious metal stream rather than a residue.
Automotive and industrial catalyst recyclers — extraction of platinum, palladium and rhodium from spent ceramic and metallic catalytic converters.
Jewellery, watch and dental manufacturing — refining of bench sweeps, polishing and buffing dust, spent plating baths and old gold and silver alloys.
Photographic, imaging and X-ray processing — recovery of silver from fixing, bleaching and developing solutions.
Mining and metallurgical operations — recovery from gold-loaded activated carbon in CIP and CIL circuits, eluate and electrowinning feed, and PGM-bearing concentrates.
Photovoltaic panel recycling — silver recovery from delaminated solar cells, cell fragments and bus bar offcuts.
Petrochemical and chemical plants — reclamation of precious metal from spent hydrogenation, reforming and coal-chemical catalysts.
Analytical laboratories and assay offices — compact recovery and refining units operating with the same documentation discipline as an industrial plant.

Applicable Raw Materials

Feedstock is grouped by physical form, because the physical form chooses the pre-treatment stage rather than the refining chemistry. The exact flowsheet for any individual stream is confirmed by laboratory test before equipment design is frozen.

Solid precious metal waste — printed circuit boards, motherboards, CPU and RAM modules, plug-in cards and chips, connectors and contact pins, mobile phone boards, electronic scrap concentrate, catalytic converters in ceramic honeycomb or metallic substrate form, spent industrial and petrochemical catalysts, PGM alloy scrap, dental and medical scrap, gold and silver doré, and old jewellery alloys. Processed by dismantling, crushing, magnetic, eddy-current, electrostatic and gravity separation, then thermal enrichment and chemical dissolution. Output: a concentrated precious-metal fraction or doré bar.

Metallurgical residues — copper anode slime, lead anode slime, zinc and nickel anode slime, tank house slimes and cell mud, refinery sweepings, glass fibre refractory brick and glass cullet carrying platinum and rhodium. Processed by washing, drying and roasting to remove copper and selenium, followed by acid leaching and selective separation of silver, gold and the platinum group metals. Output: gold and silver powder or crystal, PGM liquor, and selenium and tellurium concentrates.

High-concentration process solutions — spent gold, silver, palladium and rhodium plating baths, strip and stripping solutions, deplating solutions, iodine and iodide etching solutions, circuit board gold etching solution, cyanide and acid based process solutions, drag-out solutions and ion exchange eluate. Processed directly by electrolytic recovery with a rotating cathode. Output: metal plate, crystal or powder stripped from the cathode, ready for re-melting or for return to the plating anode.

Dilute and rinse streams — plating line rinse water, recovery tank solution, washing water, spent photographic fixing and bleach solutions, wastewater holding tank content, and process effluent. Processed by ion exchange resin and activated carbon adsorption, with cyclone electrowinning where the metal value justifies it. Output: a loaded resin or carbon eluate for the concentrated route, and treated water at parts-per-million residual metal.

Sludge and powder streams — electroplating sludge, wastewater treatment sludge, filter cake, spent catalyst powder, grinding swarf, vibration finishing and tumbling waste, and polishing slurry. Processed by drying, roasting and leaching, then capture and separation. Output: mixed precious metal concentrate and a base-metal-bearing residue.

Adsorbed and intermediate streams — gold-loaded activated carbon from CIP and CIL circuits, loaded ion exchange resin, precipitated and cemented intermediates, and silver chloride residue from the refining circuit. Processed by desorption, elution, reduction and re-leaching back into the head of the circuit. Output: pregnant solution returned to electrolysis.

Output Products

The system delivers finished, saleable metal plus the intermediates the next stage of refining needs. Each entry states the form the product leaves the plant in, the purity it is released at, and the assay behind that figure.

Gold — supplied as ingot, bar, granule or electrolytic gold powder. Refined to 99.99% (4N) as standard, with 99.999% (5N) achievable through a second electrolytic pass. Output: LBMA Good Delivery-grade bullion cast to your required bar weight, with gold anode plates and doré released as process intermediates.

Silver — supplied as electrolytic silver crystal, silver powder, granule or ingot at 99.99% purity. Output: silver crystal for industrial sale or ingot for investment and industrial use, with silver cement and silver chloride handled as in-circuit intermediates rather than as waste.

Platinum group metals — platinum sponge, palladium powder and palladium salts, and rhodium powder or rhodium chloride solution. Refined to a minimum of 99.95% for platinum and palladium and 99.90% for rhodium. Output: sponge and powder released against ICP-OES verification, or the purified salt your downstream process requires.

Copper — copper cathode, copper plate and copper powder at 99.99% purity (LME Grade A equivalent), recovered in parallel from electrolyte purification duty. Output: cathode and plate saleable on the base-metal market without further treatment.

Recovered metal plate and powder from process solutions — gold, silver and palladium plate, crystal or powder stripped directly from the rotating cathode of the recovery cell, produced at 95–99.8% purity. Output: metal ready for re-melting or for direct return to the plating anode.

Treated water and recycled process liquid — clarified, decanted or polished liquid with precious metal content reduced to parts-per-million levels. Output: water suitable for recirculation to the rinse line, reuse as coolant or cleaner, or release to the wastewater plant.

By-product streams — mixed precious metal concentrate, selenium and tellurium concentrates from anode slime treatment, base metal salts recovered from bleed treatment, and dewatered sludge that has been assayed and released. Output: secondary saleable products plus a residue certified as below the economic recovery threshold.

Process Workflow

The flowsheet combines mechanical, thermal, chemical and electrochemical stages. Which stages a project includes depends on the feedstock: a plating plant project may use only the electrochemical route, while an e-waste or anode slime project will normally use all nine steps.

Steps 1 — Feed Preparation and Assay. Incoming material is weighed, logged and sampled. The sample is characterised by XRF screening and, where precious metal content is payable, by fire assay or wet chemical analysis, so that the batch enters the circuit with a known grade and a route selected for its chemistry. Output: a homogenised, weighed batch with a representative assay and a batch identifier.

Steps 2 — Mechanical Liberation and Physical Sorting. Solid feed is dismantled, de-soldered and pre-crushed, then ground in a shredder or hammer mill to liberate metal from plastics, glass fibre and other non-metallics. Ferromagnetic material is removed by magnetic separation; metals are separated from non-metals by eddy-current or electrostatic separation on the basis of conductivity; gravity separation and vibrating shaker tables separate metal particles from lightweight impurities on the basis of density; screening sizes the material between stages. Dust and fines are captured by a dust collection system. Output: a concentrated metallic fraction and a clean non-metallic fraction.

Steps 3 — Thermal Enrichment and Volatile Removal. Organic content is burned off and volatiles are driven out in a rotary furnace or TBRC-type top-blown rotary furnace, with flux added to collect the precious metals into a base metal alloy, matte or doré. Slag is tapped, cooled and assayed before it is released, and off-gas passes to the environmental train. Output: doré bar or anode plates for dissolution, with slag returned to smelting until it is barren.

Steps 4 — Chemical Dissolution and Leaching. Prepared solid feed or concentrated residue is leached in agitated acid-resistant reactors. Gold is taken into solution through chlorination or aqua regia chemistry, silver through nitric acid or nitric parting, and platinum, palladium and rhodium through chloride media with hydrochloric acid and chlorine or oxygen as oxidant. Alkaline and cyanide chemistry is applied to specific feeds and to desorption duty. Acid concentration, oxidant addition rate, temperature and residence time are controlled and recorded per batch. Output: pregnant solution, with leach residue returned for re-treatment.

Steps 5 — Adsorption, Ion Exchange and Concentration. Metal ions are captured from pregnant or dilute solution by activated carbon adsorption, ion exchange resin or selective precipitation, according to metal concentration and solution chemistry. Concentrated solutions pass directly to electrolytic recovery; dilute streams are polished on resin or carbon columns, and cyclone electrowinning is applied where the metal value justifies it. Output: loaded carbon or resin and a concentrated eluate feeding the electrolytic stage.

Steps 6 — Selective Separation and Purification. Base metals and individual precious metals are separated in sequence using mixer-settler solvent extraction with P204, P507 and C272 systems, ion exchange, cementation and selective reduction, so that each metal reaches the purity its electrolytic stage requires. Gold is reduced and precipitated; platinum and palladium are cemented or reduced out of the raffinate; rhodium is recovered from the residual liquor. Output: separated metal liquors and purified intermediate compounds, each routed to its own refining cell.

Steps 7 — Electrolytic Recovery and Refining. Purified solutions are deposited in electrolytic cells using a rotating cathode with high-frequency pulse intelligent electrolysis on the recovery duty, and in Wohlwill-type gold cells and Möbius-type silver cells on the refining duty. On a plating line the recovery cells are installed in one of two ways: online recycling, where the cell sits beside the recovery tank behind the plating cylinder and keeps tank metal content continuously low so that less metal is carried into the following rinse stages; and offline recycling, where metal-bearing wastewater is collected in a storage tank and processed in batches, with the treated liquid released to the wastewater pool afterwards. Output: high-purity cathode gold, electrolytic silver crystal, PGM metal, and metal plate or powder stripped from the recovery cathode.

Steps 8 — Melting, Casting and Product Release. Recovered metal is dried, weighed, blended and melted in an induction melting furnace, then cast into ingots, bars or granules, or atomised into powder. Vacuum and continuous casting options improve surface quality and reduce oxidation losses. Each batch is re-assayed and released against a Certificate of Analysis naming the method used. Output: marked, weighed and documented finished product.

Steps 9 — Recirculation and Environmental Control. This step runs continuously across steps 1 to 8 rather than sequentially after them. Off-spec product, cell residues, filter cake and slag return to the appropriate upstream stage instead of leaving as waste. Nitrogen oxide and acid fumes are captured under enclosed hoods, condensed and treated in a multi-stage absorption tower. Wastewater is neutralised, precipitated, flocculated and dewatered; clarified liquid is recirculated to the process or reused as coolant and cleaner, and sludge is dried and assayed before release. Output: treated gas and water monitored to the agreed discharge limits, and metal losses closed back into the circuit.

Product Structure (Main Equipment)

The system is assembled from the following modules. Modules can be supplied individually for customers upgrading an existing plant, or as a complete system with layout, utilities design, installation, commissioning and operator training.

Mechanical pre-treatment module — dismantling benches, desoldering stations, shredder, hammer mill, crusher, screening, magnetic separator, eddy-current or electrostatic separator, gravity separation table, vibrating shaker table, and dust collection system.

Thermal treatment module — rotary furnace or TBRC-type top-blown rotary furnace, tilting crucible furnace, afterburner, flux dosing system, slag handling equipment, and enclosed off-gas ducting.

Hydrometallurgical leaching module — agitated jacketed leaching reactors in PPH, PP, FRP or enamel-lined steel construction, acid and oxidant dosing stations, dissolution and neutralisation reaction kettles, and batch control instrumentation.

Solid-liquid separation module — filter presses, cartridge and precision filtration units, centrifuge, multi-layer washing thickeners, and clear liquor storage tanks.

Adsorption and ion exchange module — activated carbon adsorption columns and ion exchange resin columns with adsorbents selected per metal and solution chemistry, elution and desorption circuit, and quick-release column connections for simplified resin replacement.

Separation and purification module — solvent extraction mixer-settler banks configured for P204, P507 and C272 duty, precipitation and reduction reactors, cementation tanks, and slurry pumps.

Electrolytic recovery module — electrolytic recovery cells with rotating cathodes and special electrodes in sealed columns, high-durability cathode assemblies, electrolyte circulation and cooling, and stripping and rinsing stations.

Electrorefining and electrowinning module — electrolytic cells in PPH, PP or PVC-lined steel with titanium cathode plates, MMO-coated titanium anodes or Pb-Ca-Sn anodes, anode bags with counter-current wash, titanium-clad copper conductive bars and bus bars, Wohlwill-type gold cells, Möbius-type silver cells, and cyclone electrowinning cells for dilute streams.

Power and rectifier module — high-frequency pulse intelligent rectifiers, IGBT rectifiers, automatic pole-reversing units, and DC bus distribution with current-density control.

Flue gas and environmental module — enclosed hoods and covers, transparent closed flue gas cover plates, flue gas condensation system, multi-stage absorption tower for nitrogen oxides and acid gas, mist eliminators, and exhaust stack with monitoring ports.

Wastewater module — neutralisation and precipitation tank, flocculation and sedimentation, filter press for sludge, ion exchange polishing, and a recirculation or zero-liquid-discharge circuit.

Melting and casting module — induction melting furnace, granulation unit, ingot moulds, vacuum or continuous casting unit, and powder atomisation unit where required.

Control and automation module — PLC and SCADA control cabinet with automatic intelligent control, recipe management per feed type, temperature, pH, ORP and current-density logging, alarm management, and remote monitoring access.

Product Features

All three recovery points in one scope — process tank, recovery tank and rinse water are treated as one flowsheet, so metal is captured before it leaves the production line rather than only at the end of the drain.
Rotating cathode with high-frequency pulse intelligent electrolysis — the moving boundary layer lets deposition continue as concentration falls, and produces a deposit that strips off cleanly as plate, crystal or powder.
No chemical reagents on the electrolytic route — recovery is a clean electrochemical reduction driven by electricity, with no electrolytic accelerators added and no secondary pollution introduced into the water circuit.
Ion exchange and activated carbon for dilute streams — adsorbents are selected against the specific metal and solution chemistry, with quick-release columns so resin replacement does not interrupt production.
Online or offline installation — cells can run continuously beside the recovery tank behind the plating cylinder, or process collected wastewater in batches from a holding tank.
Complete solid-feed flowsheet — mechanical sorting, thermal enrichment, leaching, adsorption, solvent extraction and electrolytic refining available as one integrated line rather than three separate contractors.
Compact, corrosion-resistant construction — fully anti-corrosion design in PPH, PP, FRP, PVDF or PVC-lined steel, engineered for safe operation inside a working production area.
Automatic intelligent control — PLC and SCADA control with recipe management, batch traceability and remote monitoring, so the system runs without a dedicated operator.
High-current-density electrorefining cells — titanium cathode plates, titanium-clad copper bus bars and optimised electrode spacing for stable cathode quality in the refining stage.
Metal returned to production, not to scrap — stripped plate and crystal can cover the plating anode directly, closing the loop inside the factory and reducing new metal purchases.
Treated liquid fit for reuse — clarified and polished liquid is recirculated to the rinse line or reused as coolant and cleaner, reducing fresh water intake.
Closed environmental control — enclosed hoods, flue gas condensation, multi-stage NOx and acid gas absorption, and a wastewater circuit with zero-liquid-discharge capability.
Assay-driven configuration — the flowsheet is built against fire assay, XRF and wet chemical results from your own sample, so low-grade or mixed feedstock is engineered for rather than rejected.
Batch traceability and metal balance — weighing, sampling and assay points at every stage produce a documented metal balance per batch for custody transfer, customs documentation and internal accounting.
Modular scalability — additional cells, columns or refining modules connect through standardised interfaces, so capacity is added rather than replaced.
Audit-ready documentation — operating manual, maintenance manual, P&ID, electrical drawings, instrumentation list, spare parts list and material certificates suited to local regulatory inspection.

Technical Parameters and Specifications

Values below are the standard design basis. Final parameters are fixed during process design, after the customer’s feedstock has been assayed. Parameters marked * are confirmed per project.

1. System Scope And Process Route

Parameter	Specification
Target metals	Gold (Au), Silver (Ag), Platinum (Pt), Palladium (Pd), Rhodium (Rh); Copper (Cu) as a parallel product; Ru, Ir, Se, Te on request *
Recovery points covered	Process tank, recovery tank behind the tank, and rinse water downstream *
Solid-feedstock route	Mechanical pre-treatment and physical sorting → thermal enrichment → leaching → capture, separation and electrolytic refining
Solution route — concentrated	Electrolytic recovery with rotating cathode and high-frequency pulse intelligent electrolysis
Solution route — dilute	Ion exchange resin and activated carbon adsorption, plus cyclone electrowinning where applicable *
Installation mode	Online (installed beside the recovery tank) or offline (batch processing of collected wastewater) *
Operating mode	Batch or continuous *
Scope of supply	Single module, partial line, or complete feed-to-ingot turnkey system *

2. Recovery And Yield Parameters

Parameter	Value	Basis
Comprehensive recovery rate	≥ 95%	Multi-metal feedstock, calculated per project from the batch metal balance
Electrolytic recovery rate	> 99%	High-concentration gold, silver and palladium streams *
Recovery rate, anode slime route	97–98% typical, up to > 99%	Gold and silver from copper and lead anode slime
Off-spec recirculation	Closed loop	Off-spec product, cell residues, filter cake and slag return upstream
Recovery calculation basis	(metal in feed − metal in final slag − metal in residue − metal in effluent) ÷ metal in feed	Stated in the proposal so it can be checked against your own assays

3. Product Purity Parameters

Product	Purity	Form
Gold	99.99% (4N) standard; 99.999% (5N) on a second electrolytic pass	Ingot, bar, granule, electrolytic powder
Gold stripped directly from the recovery cathode	95–99.8%	Plate, crystal or powder for re-melting
Silver	99.99%	Electrolytic crystal, powder, granule, ingot
Platinum	≥ 99.95%	Sponge or ingot
Palladium	≥ 99.95%	Powder, sponge or purified salt
Rhodium	≥ 99.90%	Powder or chloride solution
Copper	99.99% (LME Grade A equivalent)	Cathode, plate, powder
Residual metal in treated liquid	Silver below 5–20 ppm; gold below 2–10 ppm *	Clarified or polished liquid for reuse or discharge

4. Electrolytic And Process Parameters

Parameter	Specification
Cell body material	PPH, PP, FRP, PVDF or PVC-lined steel *
Cathode	Rotating cathode in recovery cells; titanium cathode plate or sheet in refining cells *
Anode material	MMO-coated titanium anode; Pb-Ca-Sn anode for base metal duty; graphite where required *
Conductive bar and bus bar	Titanium-clad copper
Anode containment	Anode bag or diaphragm in acid-resistant fabric or PTFE, with counter-current wash circuit
Rectifier and power supply	High-frequency pulse intelligent rectifier; IGBT rectifier with automatic pole reversing
Cathode current density	Up to 1000–1200 A/m² for gold electrolysis; 300–800 A/m² for silver electrolysis *
Electrolyte temperature	Gold electrolyte 60–70 °C; silver electrolyte controlled at ≤ 50 °C via cooling circuit *
Temperature control accuracy	± 1 °C in electrolytic refining cells
Electrolyte circulation	Closed-loop with continuous filtration
Leaching chemistry	Aqua regia and chlorination for gold and PGM; nitric acid and nitric parting for silver; chloride, alkaline and cyanide media for specific feeds *
Separation chemistry	Solvent extraction with P204 / P507 / C272, ion exchange resin, activated carbon adsorption, selective precipitation, cementation
Reagent consumption	None on the electrolytic recovery route (electricity only); reagents used and metered per batch in leaching and separation

5. Materials Of Construction

Stream or equipment	Material options
Reaction and dissolution vessels	Enamel-lined steel, PPH, PP, PVDF, PTFE-lined
Acid and chloride tanks	PPH, PVC, PVDF, FRP
Wetted parts, pumps and fittings	PTFE, PVDF, titanium, 316L stainless steel
Electrolytic cell bodies	PPH, PP, PVC-lined steel, PTFE or PVDF-lined; concrete or FRP shells for large cells
Cathode and anode substrates	Titanium, stainless steel, graphite, precious-metal-coated
Off-gas ducting and scrubbers	PPH, FRP, PVC

6. Control, Utilities And Environmental Parameters

Parameter	Specification
Control system	PLC + SCADA with automatic intelligent control, recipe management per feed type and remote monitoring
Instrumentation	Temperature, pH, ORP, conductivity, flow, current density, level
Data logging	Batch-based recording of process parameters and metal balance
Off-gas treatment	Enclosed hoods + flue gas condensation + multi-stage absorption tower; NOx removal efficiency ≥ 99%, outlet concentration set to the local permit limit *
Wastewater treatment	Neutralisation, precipitation, flocculation, sludge dewatering, ion exchange polishing; recirculation with zero-liquid-discharge option
Power supply	380 V / 415 V / 440 V, 50 Hz or 60 Hz, three-phase; configured to the local grid and standard *
Utilities	Process water, cooling water, compressed air, exhaust ventilation; steam only for stages requiring elevated temperature
Capacity basis	Defined per project as batch mass × cycles per day from your feed grade and target output; scaled by module count rather than by a single fixed model size *
Installation form	Modular skid-mounted or site-assembled, with CAD / 3D plant layout provided

7. Assay, Verification And Product Release

Stage	Method	Reference standard
Feed sampling and assay	Representative sampling, XRF screening, fire assay or wet chemical analysis	ISO 11426, ASTM E1335
In-process control	Titration, ORP and specific-ion measurement	Per project
High-purity gold, platinum, palladium	Difference method by ICP-OES	ISO 15093
High-purity silver	Difference method by ICP-OES	ISO 15096
Final product release	Fire assay to 999.5‰, or ICP-OES difference above that fineness	ISO 11426, ISO 15093, ISO 15096
Good Delivery compliance	Fineness against LBMA Good Delivery minimum (995.0 gold, 999.0 silver)	LBMA Good Delivery Rules

Important. Precious metal recovery and refining involves strong acids, chlorine gas, nitrogen oxides and molten metal. Do not scale or operate a process from published text alone. Final design must be validated by our engineers against your specific feed, local regulations and site conditions.

Technical Advantages

A complete system instead of a single machine. Most suppliers offer either an electrolytic cell for plating waste or a shredder-and-furnace line for e-waste. YuSai supplies both ends of the problem and the chemistry that connects them, which is why one project can treat a spent plating bath, the drag-out behind it, the rinse water downstream and the solid sludge from the wastewater plant without three separate contractors and three sets of interface risk.

Recovery that continues as concentration falls. The rotating cathode keeps the cathode boundary layer in motion, so deposition does not stall at the high-concentration stage and the cell keeps pulling metal out of solution into the low parts-per-million range. This is the difference between a recovery unit that harvests only the easy metal and one that actually reduces what leaves the site.

Recovery is stated on a defined basis. We publish the metal-balance formula behind every recovery figure, so the number can be checked against your own assays instead of being accepted on trust. Most listings in this category assert a percentage with no basis at all.

Purity claims come with the assay method attached. Naming ISO 11426, ASTM E1335, ISO 15093 and ISO 15096 makes each figure independently reproducible — which matters when your own buyer assays the ingot on arrival.

Fewer consumables, lower running cost. On the electrolytic route no chemical reagents, reducing agents or electrolytic accelerators are consumed; the recovery step costs electricity. Ion exchange resin and activated carbon are regenerated or replaced on a schedule through quick-release columns, so maintenance does not require production downtime.

Metal returned to production, not to scrap. Recovered plate and crystal can be taken directly to the anode side of the plating process, closing the loop inside the factory and reducing the amount of new metal that has to be purchased.

Environmental compliance inside the scope of supply. Off-gas capture, condensation, multi-stage absorption and wastewater treatment are engineered together with the process, with defined performance targets, rather than procured afterwards from a third party. This is normally the single largest cause of permitting delay on a recovery project.

Design based on your sample, not a catalogue. Because equipment selection is driven by assay and bench-scale test results, low-grade or mixed feedstock is engineered for rather than rejected, and the customer sees the expected mass balance before signing.

Feed disqualification is stated up front. Saying what the system cannot process protects the project schedule and the commercial relationship, and it is the information buyers look for after a poor experience elsewhere.

Working capital is treated as a design variable. The precious metal immobilised in electrolyte, anode plates and in-process inventory is quantified in every proposal, because that metal is a real cost of ownership rather than a rounding item.

Losses are recycled, not written off. Slag, residues, filter cake and off-spec product re-enter the circuit instead of leaving as waste, which raises effective yield without adding feed.

Documentation is audit-ready. P&IDs, instrumentation lists, procedures, batch records and certificates are supplied as a controlled set, so quality-system audits and customer claims do not require reconstruction.

Service Flow

Inquiry and Process Consultation — share your feedstock or process stream, its current handling route and your target metals. We respond with a preliminary recovery route and the sample quantity and information required for testing.
Raw Material Testing and Assay — we analyse your sample by fire assay, XRF and wet chemical analysis and run bench-scale leaching, adsorption and deposition tests, then issue a test report stating recoverable metal content, expected recovery rate and the proposed separation sequence.
Process Design and Flowsheet — based on the test report we prepare a process flow diagram, mass balance, equipment list, utility requirements and a CAD or 3D plant layout matched to your site, including the position of tank-side recovery cells on an existing plating line.
Quotation and Contract — a detailed commercial proposal covering equipment scope, spares, documentation, shipping terms and service scope, with the lead time stated as a commitment rather than an estimate.
Detailed Engineering — P&IDs, equipment specifications, electrical and control design, plant layout and the emission and effluent data needed to support your permit applications.
Manufacturing and Factory Acceptance Test — fabrication follows the approved drawings and materials specification. Key equipment is assembled and tested at the factory, and a factory acceptance test report with photographs and video is issued before shipment.
Packing, Shipping and Documentation — equipment is export-packed and container-loaded with a full shipping document set, including packing list, certificate of origin and the technical documentation package.
Site Installation — our engineers attend site to supervise mechanical erection, electrical and piping connection, water and gas commissioning and trial production.
Commissioning and Metal Balance Verification — cold and hot commissioning, tuning of process parameters on your actual feed, and verification of the batch metal balance. The system is handed over only after it produces metal at the agreed specification.
Operator Training and Handover — operating and maintenance personnel are trained on process control, reagent handling, safety procedures, sampling and assay routines and daily maintenance. Written manuals and video guides are supplied.
After-Sales Support — remote and on-site technical support, spare parts supply, periodic service visits, process optimisation and upgrade or retrofit service for the operating life of the system.

Warranty And After-Sales

Warranty. Equipment supplied by YuSai Machinery carries a standard warranty period from the date of commissioning or shipment, covering defects in materials and workmanship under normal operating conditions. Wear parts, consumable electrodes, anode bags and diaphragms, filter cloth, resin and carbon charges, reagents, glassware, refractory lining and items damaged by improper operation or unauthorised modification are excluded and are listed with their expected service life in the spare parts schedule. Warranty terms are confirmed in the contract for each project.

Spare parts. Critical spares — cathode assemblies and electrode plates, anode bags, resin and carbon replacement charges, gaskets, seals, pump components, filter media and rectifier modules — are quoted with the original order and can be supplied afterwards at cost-based pricing. A recommended first-year spare parts list is issued with the technical documentation, and critical spares remain available for the operating life of the plant.

Technical support. Online technical support is available on a continuous basis, with remote diagnosis of control system data where the plant is connected. Where a fault cannot be resolved remotely, our engineers can attend site under the terms of the service agreement.

Installation and training. Site installation supervision, commissioning, metal balance verification and operator training are part of the standard delivery scope. Follow-up training visits and refresher sessions can be scheduled after the system has been running in production.

Process optimisation and upgrades. Because the system is modular, stages can be added or modified later — extra recovery cells, additional resin or carbon columns, automatic cathode handling, an added separation circuit, or an upgrade of the control system. We also carry out process reviews based on the customer’s own operating data and assay records when the feed mix changes.

Documentation. Each project is delivered with an operating manual, maintenance manual, electrical drawings, P&ID, instrumentation list, spare parts list, material certificates and a commissioning report, in a format suitable for local regulatory inspection.

Frequently Asked Questions

What is a precious metal recovery and extraction system?
A precious metal recovery and extraction system is an integrated process plant that recovers gold, silver, platinum, palladium and rhodium from solid waste, concentrated process solutions and dilute effluent, then refines those metals into assayed product. It normally combines mechanical pre-treatment, thermal enrichment, chemical dissolution, selective separation by solvent extraction and ion exchange, and electrolytic refining, together with the off-gas and wastewater treatment that make the circuit licensable.

How is a recovery system different from an extraction system?
Recovery is the capture step: pulling metal out of a stream that would otherwise lose it, typically process solutions, rinse water and effluent. Extraction is the liberation step: breaking down solid feedstock such as circuit boards, anode slime and spent catalysts so the metal can be dissolved and separated. A complete YuSai system does both in one flowsheet, which is why the same project can treat plating waste and solid residue without a second contractor.

Which precious metals can this system recover?
Gold, silver, platinum, palladium and rhodium are the primary target metals, with copper recovered in parallel as a cathode product. Ruthenium, iridium, selenium and tellurium can be included in the flowsheet when the feedstock carries them in economic quantities.

What purity can the finished metal reach?
Gold and silver are refined to 99.99% (4N) as standard, and gold can reach 99.999% (5N) through a second electrolytic pass. Platinum and palladium are delivered at a minimum of 99.95%, rhodium at a minimum of 99.90%, and copper cathode at 99.99%. Gold stripped directly from the recovery cathode is produced at 95–99.8% purity and is then refined further.

What is the recovery rate?
The standard design target is 95% or higher comprehensive recovery on multi-metal feedstock, and the electrolytic route achieves more than 99% recovery on high-concentration gold, silver and palladium streams. On the anode slime route, gold and silver recovery of 97–98% is typical and can exceed 99%. Actual recovery depends on the grade and matrix of the feedstock and is confirmed by the raw material test.

How is the recovery figure calculated?
Recovery is not a fixed property of the equipment; it is the metal balance of your specific feed, calculated as metal in feed minus metal in final slag, residue and effluent, divided by metal in feed. Two plants with identical equipment and different feed will report different recoveries, so we state the basis rather than only the number, and you can check it against your own assays.

Which raw materials are suitable?
Electronic scrap and board fractions, spent plating baths, drag-out and rinse water, stripping and etching solutions including iodine and iodide etching solutions, spent photographic fixing solutions, anode slime from copper, lead, zinc and nickel refining, spent automotive, petrochemical and fuel-cell catalysts, jewellery scrap and polishing sweeps, PGM alloy scrap, plating sludge, gold-loaded activated carbon from CIP and CIL circuits, photovoltaic silver streams and mining concentrates.

Which materials can the system NOT process?
Mixed feed with no assay, base-metal-dominant feed without a preceding removal stage, high-grade silver or silver halide material sent directly to gold electrolysis, hazardous waste without the corresponding handling licence at the destination site, and feed containing mercury, thallium or high-concentration cyanide without a dedicated abatement module. We will tell you before quoting if your material falls into one of these categories.

How do I know whether my material or wastewater can be processed?
Send a representative sample. We analyse it by fire assay, XRF and wet chemical analysis and run bench-scale leaching, adsorption and deposition tests, then issue a test report stating the recoverable metal content, the expected recovery rate and the proposed separation sequence. Equipment design is based on that test report rather than on assumptions.

Which route should I choose — electrolytic, hydrometallurgical or pyrometallurgical?
It depends on the feed. Electrolytic recovery suits concentrated solutions such as plating baths and strip solutions, and is the lowest-cost route because it consumes only electricity. Hydrometallurgical leaching suits solid feed where the matrix can be dissolved, and gives the highest selectivity for platinum group metals. Pyrometallurgical enrichment is used first when the feed contains organics or a high proportion of base metal. The proposal includes a route-selection comparison for your material.

Can the system be installed on an existing plating line?
Yes. Recovery cells can be installed online, beside the recovery tank behind the plating cylinder, so that tank metal content is kept continuously low and less metal is carried into the following rinse stage. The same cell can be used offline, processing collected wastewater in batches from a holding tank.

What metal concentration is left in the treated liquid?
On the electrolytic route, treated liquid is typically reduced to below 5–20 ppm silver and below 2–10 ppm gold, with ion exchange or activated carbon polishing applied where lower residual levels are required. The target figure for each project is fixed during process design against your discharge standard.

Does the recovery process need chemical reagents?
Not on the electrolytic route. Electrolytic recovery consumes only electricity and adds no chemical reagents, reducing agents or accelerators to the stream, so there is no secondary pollution to manage. Reagents are used in the leaching and separation stages of the solid-feedstock route, where they are metered and recorded per batch.

How is nitrogen oxide and acid gas handled?
Dissolution and electrolysis are carried out under enclosed hoods. Fumes pass through a flue gas condensation system and then a multi-stage absorption tower before discharge, with removal efficiency above 99% and outlet concentration set to match the local permit limit.

Can the system run with no liquid discharge?
Yes. Process water is recirculated, and the bleed stream passes through neutralisation, precipitation and ion exchange polishing. Clarified water is reused as process water, coolant or cleaner, and a zero-liquid-discharge configuration is available where local regulations or site constraints require it.

How is the purity figure verified?
Fire assay to ISO 11426 or ASTM E1335 for gold-bearing material, XRF screening in process, and ICP-OES difference analysis to ISO 15093 for gold, platinum and palladium and ISO 15096 for silver. Every consignment is released with a Certificate of Analysis naming the method used, so a third-party laboratory can reproduce the result.

What power supply and utilities are required?
The electrical design is configured to your site: 380 V, 415 V or 440 V, 50 Hz or 60 Hz, three-phase. Process water, cooling water, compressed air and exhaust ventilation are the main utilities, with steam required only for stages that need elevated temperatures. The electrochemical recovery route itself draws power in the low kilowatt class.

How much space does the system need?
Footprint depends on capacity and the number of stages included. Compact recovery units are designed for installation inside a working production area. For full systems we prepare a CAD or 3D layout against your actual building or yard dimensions during process design, and multi-level arrangements are used where floor area is limited.

Do you provide installation and training?
Yes. Site installation supervision, commissioning, metal balance verification and operator training are part of the standard scope. The system is handed over only after it produces metal at the agreed specification, and operating and maintenance manuals are supplied in written and video form.

Can capacity be increased later?
Yes. The system is modular and capacity is scaled by adding modules rather than by replacing it, so additional leaching, separation, electrolytic or refining stages can be connected to the existing plant through standardised interfaces.

Is a small unit available for laboratories or small workshops?
Yes. Compact systems are available for laboratories, assay offices, jewellery workshops and small plating lines, and they use the same cell and control architecture as the industrial line, which allows a process to be validated on a small scale before investment is expanded.

How much does a precious metal recovery and extraction system cost?
Cost is driven by the feedstock, the number of process stages, the degree of automation and the environmental modules required, so a quotation is prepared after the raw material test rather than from a fixed list price. Modular construction also allows a project to be implemented in phases, starting with the stream that causes the greatest metal loss.

What do I need to send for a quotation?
A representative feed sample — typically a few kilograms, or a few litres for a solution stream — plus your target output and site conditions. The assay result is the single input that determines route, recovery projection, equipment list and price. Sampling and the feed assay are returned with the proposal.

How long is delivery and commissioning?
Standard modules and single units ship first; complete turnkey systems take longer because engineering is done against your assay. Installation and commissioning add site time depending on scope. Firm lead times are stated in the quotation.

What environmental approvals will I need?
Typically air emission approval for acid fumes and nitrogen oxides, effluent discharge consent for process water, and hazardous waste handling registration for acid residues and sludge. We supply the emission and effluent data needed to support your local permit application.